A year after treatment with Athersys Inc.'s Multistem cell therapy in a phase II trial, 23 percent of people who suffered an ischemic stroke achieved a clinically rated "excellent outcome" vs. just 8.2 percent of patients who received placebo, the company told attendees of the 2016 International Stroke Conference in Los Angeles. Those results, which bested Multistem's 90-day benefit, lifted Athersys shares (NASDAQ:ATHX) 16.6 percent to close at $1.69 on Thursday.

The report reads further in to top-line data Athersys released in April 2015, at which point it disclosed that the trial had missed its primary and secondary endpoints, but still yielded valuable information regarding the multipotent adult progenitor cell therapy's ability to modulate the immune system following stroke. (See BioWorld Today, April 20, 2015.)

Athersys' president and chief operating officer, B.J. Lehmann, told BioWorld Today the new data are exciting "because [they] provide further confirmation and validation that we're seeing something with Multistem that really justifies further development" and that illustrates "the potential of an entirely different treatment approach to stroke patients."

At the one-year mark, more Multistem-treated patients in the company's intent-to-treat population fared well than those receiving placebo, with many achieving the "excellent outcome" criteria, as defined by achievement of a modified Rankin Scale score of 0 to 1 (meaning that their conditions ranged from no symptoms to no significant disability), an NIH Stroke Scale score of 0 to 1 (where 0 means no stroke symptoms) and a Barthel Index score of 95 or greater (with higher numbers corresponding to greater post-stroke independence).

Among all subjects enrolled in the trial, 61.5 percent of Multistem patients had an excellent outcome in the Barthel Index (≥95) vs. 44.3 percent of placebo patients (p=0.05); Among the 31 Multistem patients who had treatment within 36 hours, 67.7 percent achieved an excellent Barthel outcome, representing a 23.4 percent difference with the incidence for all placebo patients (p=0.03).

The randomized, double-blind, placebo-controlled trial was conducted at sites in the U.S and the U.K. It enrolled subjects who received either Multistem treatment or placebo via intravenous administration one to two days following their strokes.

Next up, Cleveland-based Athersys is planning to launch two new phase III stroke studies, most likely this year: one in Japan with its partner, Tokyo-based Healios K.K., and another in North America and Europe. Both trials would focus on treating the same patient population as those who were enrolled in the phase II study, patients with moderate to severe stroke. Patients in both would be treated within 36 hours, the window in which treatment with Multistem has been shown to yield the greatest benefit. "The data from both the interim readout and the analysis we did around that and the data from one year, confirm that we have a target population in which it makes sense to move forward in development," said Lehmann.

"Multistem's treatment benefit appears to be deepening with time," wrote Edward Tenthoff, a senior analyst for Piper Jaffray & Co. However, despite the positive data and further validation, he noted that Athersys and Healios still need to perform the Japanese trial and that "the U.S. regulatory path remains unclear." Tenthoff holds a "neutral" rating on the stock.

In Japan, Lehmann said Healios would be a great partner for Athersys. The parties had connected prior to Athersys' now defunct partnership with Chugai Pharmaceutical Co. Ltd. That deal unraveled after Chugai sought a renegotiated deal with Athersys after the release of the top-line phase II data in April.

Athersys is developing Multistem to improve tissue repair and healing in multiple ways, including through the reduction of inflammatory damage, the protection of tissue that is at risk following acute or ischemic injury and the promotion of new blood vessel formation in regions of injury. Athersys has explored its use as a treatment for acute and chronic forms of neurological conditions, cardiovascular disease, inflammatory and immune disorders and certain pulmonary conditions.

On Dec. 17, the company arranged a new equity facility with Aspire Capital, replacing a prior two-year equity arrangement with the Chicago-based investment fund. Under the new agreement, detailed in a Jan. 14 regulatory filing with the SEC, Athersys has the right to sell up to $30 million of shares of common stock to Aspire under certain conditions.

The company had $28.5 million in cash and cash equivalents available to fund its operations as of Sept. 30.